Epidemiological investigations are unable to explain sex differences in coronary heart disease (CHD). The applicants propose that to the extent that individual differences in cardiovascular, neuroendocrine, and metabolic responses to behavioral challenge are a risk factor for CHD, sex differences in stress responses may assist in explaining sex differences in CHD. The ongoing research program has documented differences in psychological responses to acute stress between men and women and among women who vary in reproductive hormone status. Building on these findings, but also departing from previous efforts in strategy and design, the continuation application proposes five studies. Study 1 will measure hemodynamic measures that underlie sex differences in cardiovascular responses to behavioral challenge. Using longitudinal designs, Study 2 will compare women's stress responses prior to and three months after surgical menopause, whereas Study 3 will compare healthy women's stress responses prior to and three months after a "temporary menopause" due to the administration of a GnRH agonist. In both studies, some women after the second testing will be administered estrogen replacement therapy and stress responses will again be measures. Thus, Studies 2 and 3 will also address the effects of estrogen replacement therapy on stress responses. These studies gain significance from the fact that surgical menopause is associated with heightened risk for CHD, whereas estrogen replacement therapy is associated with protection from CHD. Study 4 will describe the extent of sex differences in exposure to psychological stressors among men and women from two levels of social class. Social class is included in the design because it is a risk factor for psychological stress and for CHD. The final study will test the hypothesis that sex differences in stress responses will be attenuated during a task within a feminine area of competency and accentuated during a task within a masculine area of competency.